This reference fin the Fall 2011 Edition of the Journal of Neuroscience shares some exciting information that provides hope for those who have suffered vision loss:

Sheila Nirenberg of Weill Cornell Medical College presented research on how the eye’s own computational “code” can improve retinal prosthetics. Retinal prosthetic devices now exist, but current models require surgery to implant electrodes into the eye and are only capable of restoring crude vision, such as seeing a spot of light or the edge of an object.

Normally, photoreceptors in the retina collect visual information, which is transmitted to retinal ganglion cells and then on to the brain. During retinal-degenerative diseases, photoreceptors and other circuitry dies, but ganglion cells maintain their connections to the brain. Nirenberg’s past work has focused on understanding the code of action potentials that neurons in the eye use to transmit visual information. In the current study, she converted images into that neural code and transmitted it to ganglion cells in mice. Encoding the information allowed the ganglion cells to send nearly normal signals to the brain, Nirenberg showed, presumably resulting in more natural vision.

Although traditional retinal prosthetics are electrode-based, Nirenberg’s system operates via optogenetics — she uses gene therapy to express channel rhodopsin in mouse ganglion cells, enabling them to respond to light pulses. She foresees the same technology might one day be available to help restore vision in people, using the same gene therapy approach and glasses containing a camera, a signal encoder, and an array of lights.

Together, these studies describe technological advances in the brain-machine interface that in the short term help neuroscientists to investigate how the brain processes information and in the long term may benefit those afflicted by injury or disease. Press conference moderator Nicolelis noted that many of the technologies examined in these studies are becoming more portable, making them more practical for use in a wide range of settings. In addition to addiction, stroke, and retinal degeneration, the speakers noted that brain-machine interface studies may be particularly suited to restoring mobility and communication for people with spinal cord injury, paralysis, and ALS..